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https://issues.apache.org/jira/browse/HDFS-8833?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14734538#comment-14734538
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Kai Zheng commented on HDFS-8833:
---------------------------------
Hi [~zhz],
Thanks for your update. We experimentally tried the large patch on a cluster
and it works fine.
One observation is, looks like we support to set ec policy on the file system
root '/', then how to unset the policy or allow to store some files in
replication in the same cluster? If not possible, then the setting may be
affecting too much.
A quick check of the codes for minor things. Better to be fixed. Thanks.
{noformat}
grep -i zone HDFS-8833-HDFS-7285.07.patch |grep '^+'
+ fail("Erasure coding zone on non-empty dir");
+ assertExceptionContains("erasure coding zone for a non-empty directory",
e);
+ .setErasureCodingPolicy("/eczone", null);
+ dfs.setErasureCodingPolicy(zone, null);
{noformat}
> Erasure coding: store EC schema and cell size in INodeFile and eliminate
> notion of EC zones
> -------------------------------------------------------------------------------------------
>
> Key: HDFS-8833
> URL: https://issues.apache.org/jira/browse/HDFS-8833
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Components: namenode
> Affects Versions: HDFS-7285
> Reporter: Zhe Zhang
> Assignee: Zhe Zhang
> Attachments: HDFS-8833-HDFS-7285-merge.00.patch,
> HDFS-8833-HDFS-7285-merge.01.patch, HDFS-8833-HDFS-7285.02.patch,
> HDFS-8833-HDFS-7285.03.patch, HDFS-8833-HDFS-7285.04.patch,
> HDFS-8833-HDFS-7285.05.patch, HDFS-8833-HDFS-7285.06.patch,
> HDFS-8833-HDFS-7285.07.patch
>
>
> We have [discussed |
> https://issues.apache.org/jira/browse/HDFS-7285?focusedCommentId=14357754&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14357754]
> storing EC schema with files instead of EC zones and recently revisited the
> discussion under HDFS-8059.
> As a recap, the _zone_ concept has severe limitations including renaming and
> nested configuration. Those limitations are valid in encryption for security
> reasons and it doesn't make sense to carry them over in EC.
> This JIRA aims to store EC schema and cell size on {{INodeFile}} level. For
> simplicity, we should first implement it as an xattr and consider memory
> optimizations (such as moving it to file header) as a follow-on. We should
> also disable changing EC policy on a non-empty file / dir in the first phase.
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